<template>
  <div id="home">
    <nav-bar class="home-nav">
      <div slot="center">购物街</div>
    </nav-bar>
    <tab-control :titles="['流行', '新款', '精选']" class="tab-control" @tabclick="tabclick" ref="tabControl1" v-show="isTabFixed"></tab-control>

    <scroll class="content" ref="scroll" :probe-type="3" @scroll="contentScroll" :pull-up-load="true" @pullingUp="loadMore">
      <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad"></home-swiper>
      <recommend-view :recommends="recommends"></recommend-view>
      <feature-view></feature-view>
      <tab-control :titles="['流行', '新款', '精选']" class="tab-control" @tabclick="tabclick" ref="tabControl2"></tab-control>
      <goods-list :goods="showGoods"></goods-list>
    </scroll>
    <back-top @click.native="backClick" v-show="isShowBackTop"></back-top>
  </div>
</template>

<script>
import HomeSwiper from './childComps/HomeSwiper'
import RecommendView from './childComps/RecommendView'
import FeatureView from './childComps/FeatureView'

import NavBar from 'components/common/navbar/NavBar'
import TabControl from 'components/content/tabControl/TabControl'
import GoodsList from 'components/content/goods/GoodsList'
import Scroll from 'components/common/scroll/Scroll'
import BackTop from 'components/content/backtop/BackTop'

import { getHomeMultidata, getHomeGoods } from 'network/home'
// import { debounce } from 'common/utils'
import { itemListenerMixin } from 'common/mixin'

export default {
  name: 'Home',
  components: {
    HomeSwiper,
    RecommendView,
    FeatureView,
    NavBar,
    TabControl,
    GoodsList,
    Scroll,
    BackTop
  },
  mixins: [itemListenerMixin],
  data() {
    return {
      banners: [],
      recommends: [],
      goods: {
        pop: { page: 0, list: [] },
        new: { page: 0, list: [] },
        sell: { page: 0, list: [] }
      },
      currentType: 'pop',
      isShowBackTop: false,
      tabOffsetTop: 0,
      isTabFixed: false,
      saveY: 0
    }
  },
  created() {
    //请求多个数据
    this.getHomeMultidata()
    // 请求商品数据
    this.getHomeGoods('pop')
    this.getHomeGoods('new')
    this.getHomeGoods('sell')
  },
  mounted() {
    // const refresh = debounce(this.$refs.scroll.refresh)
    // //对监听事件进行保存
    // this.itemImgListener = () => {
    //   refresh()
    // }
    // //监听item中图片加载完成
    // this.$bus.$on('itemImageLoad', this.itemImgListener)
  },
  destroyed() {
    console.log('home destroy')
  },
  activated() {
    this.$refs.scroll.scrollTo(0, this.saveY, 0)
    this.$refs.scroll.refresh()
  },
  deactivated() {
    //1.滑动的位置 保存y值
    this.saveY = this.$refs.scroll.getScrollY()
    // console.log(this.saveY)
    // 2.取消全局事件监听
    this.$bus.$off('itemImageLoad', this.itemImgListener)
  },
  computed: {
    showGoods() {
      return this.goods[this.currentType].list
    }
  },
  methods: {
    /**事件监听
     **/

    tabclick(index) {
      switch (index) {
        case 0:
          this.currentType = 'pop'
          break
        case 1:
          this.currentType = 'new'
          break
        case 2:
          this.currentType = 'sell'
          break
      }
      this.$refs.tabControl1.currentIndex = index
      this.$refs.tabControl2.currentIndex = index
    },
    //点击回顶
    backClick() {
      this.$refs.scroll.scrollTo(0, 0, 500)
    },
    //监听滚动事件
    contentScroll(position) {
      //判断BackTop是否显示
      this.isShowBackTop = -position.y > 1000
      // 决定tabControl是否吸顶(position:fixed)
      this.isTabFixed = -position.y > this.tabOffsetTop
    },
    //上拉加载更多
    loadMore() {
      this.getHomeGoods(this.currentType)
    },
    swiperImageLoad() {
      //获取tabControl的offsetTop
      //所有组件都用一个属性$el:用于获取组件中的元素
      this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
    },
    /**网络请求
     * */
    getHomeMultidata() {
      getHomeMultidata().then(res => {
        // console.log(res)
        this.banners = res.data.banner.list
        this.recommends = res.data.recommend.list
      })
    },
    getHomeGoods(type) {
      const page = this.goods[type].page + 1
      getHomeGoods(type, page).then(res => {
        // console.log(res)
        this.goods[type].list.push(...res.data.list)
        this.goods[type].page += 1
        //完成了下拉加载更多
        this.$refs.scroll.finishPullUp()
      })
    }
  }
}
</script>
<style scoped>
#home {
  /* height: 10000px; */
  /* padding-top: 44px; */
  height: 100vh;
  position: relative;
}
.home-nav {
  background-color: var(--color-tint);
  color: #fff;
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 999;
}
.tab-control {
  position: sticky;
  top: 44px;
  background-color: #fff;
  z-index: 999;
}
/* .tab-control {
  position: relative;
  z-index: 9;
  background-color: #fff;
} */
.content {
  position: absolute;
  top: 44px;
  bottom: 49px;
  left: 0;
  right: 0;
  /* overflow: hidden;   */
}
</style>
